How to remove or prevent yellow rust on 304 stainless steel
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I heard that the crystallization tanks made of 304 stainless steel I use develop yellow rust in alkaline environments. Why is that?
Is the 304 grade resistant to alkalis due to alkali crystals?
Caustic soda contains a high level of chloride ions. Generally, for 304 material, the specified limit for chloride ion concentration in the medium is no more than 50 ppm, with 20 ppm being the recommended value. Clearly, ordinary caustic soda solutions do not meet this standard; it may be necessary to use alternative materials such as steel lined with PTFE.
Are the chloride ion concentration values you mentioned accurate? Could you give me some relevant knowledge? ! Thank you! ! !
The details are discussed in great depth in this post: http://bbs.hcbbs.com/viewthread.php?tid=511431
Thank you; this is useful information. Does this fall under internal reactions in metals?
Because of the high concentration of chloride ions in alkalis, corrosion tends to occur easily when salts are present